Curing processes nanocomposites

There is a strong necessity to define formulations components processes conditions for nanostructured materials filled by metallic additives. Another task is optimization of components, nanocomposites and diluents combination and, in what follows, curing processes with determined temperature mode. The result of these arrangements will be materials with layerwise homogeneous metal particles/nanocomposites distribution formulation in ligand shell. 

Kumar, V, Goel, NK, Francis, S, Bhardwaj, YK, Varshney, L. 2012. Hybrid organic/inorganic nanocomposite coating by electron beam curing process, Proceedings of the 18th International Symposium on Thermal Analysis, Mumbai, India, pp. 269-271. 

Chakrabarty, S. Zhang, X. Bharti, P. Chujo, Y. Miyake, J. Wynne, K. J. Ya-davaUi, V. K., Processing Dependence of Surface Morphology in Condensation Cured PDMS Nanocomposites. Polymer 2010, 51, 5756-5763. 

On the other hand, the results of a DSC analysis performed to investigate the curing process of nitrile rubber (NBR)-layered clay nanocomposites showed a... 

Other epoxy-based nanocomposites were obtained by the same dual-cure process using a novel epoxy oligomer, namely 3-isocyanatopropyltriethoxysilane (IPTS)-grafted bisphenol A epoxy resin, and tetraethyl orthosilicate as inorganic precursor [273]. The in situ generated Si02 nanoparticles (approx. 40 nm in diameter) were homogeneously dispersed inside the matrix, as evidenced by TEM, and they imparted improved thermal and mechanical properties to nanocomposites. 

Malucelli, G., Priola, A., Sangermano, M., et al. Hybrid nanocomposites containing silica and PEG segments preparation through dual-curing process and characterization. Polymer 46, 2872-2879 (2005)... 

Real-time infirared spectroscopy proved particularly well suited to check whether the silicate platelets have any effect on the UV-curing process. The polymerization profiles recorded for a 25 /um thick polyurethane-acrylate film (Fig. 7.5) clearly show that the organoclay (5 wt.%) has no slowing down effect on the polymerization reaction which proceeds as extensively in the nanocomposite as in the unfilled resin. It means that the mineral filler is not acting as a radical scavenger and that the penetration of UV radiation into the sample is not reduced significantly by the nanoparticles. This is also true for up to 2 mm thick samples, where similar polymerization profiles were recorded... 

Temperature dependence of rate constant characterizing curing processes of epoxy and its composites at 2.17 vol.% nanosilica content (reprinted from Wear, vol. 253, M. Q. Zhang eta .. Effect of particle surface treatment on the tribological performance of epoxy based nanocomposites, p. 1086,2002, with permission from Elsevier). 

Maiti et al. [64] took typical fluorocarbon-based exfoliated nanocomposites and observed that they reagglomerate while they are processed in a hydraulic press during the curing operation. Their XRD studies revealed that the level of exfoliation was, however, not disturbed if oven curing was performed, instead of press curing. 

Figure 7 shows the representative bright field HRTEM images of nanocomposites of NR and unmodified montmorillonite (NR/NA) prepared by different processing and curing techniques. It is apparent that the methodology followed to prepare the nanocomposites by latex blending facilitates the formation of exfoliated clay structure, even with unmodified nanoclays. It has been reported in the literature that hydration of montmorillonite clay leads to extensive delamination and breakdown of silicate layers [94, 95]. It has also been shown that NA disperses fully into the individual layers in its dilute aqueous dispersion (clay concentration <10%)... 

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